The alleged murder of Kate Steinle in San Francisco by illegal immigrant Juan Francisco Lopez-Sanchez has reignited the debate over the link between immigration and crime. Such debates often call for change in policy regarding the deportation or apprehension of illegal immigrants. However, if policies should change, it should not be in reaction to a single tragic murder. It should be in response to careful research on whether immigrants actually boost the U.S. crime rates. With few exceptions, immigrants are less crime prone than natives or have no effect on crime rates. As described below, the research is fairly one-sided. There are two broad types of studies that investigate immigrant criminality. The first type uses Census and American Community Survey (ACS) data from the institutionalized population and broadly concludes that immigrants are less crime prone than the native-born population. It is important to note that immigrants convicted of crimes serve their sentences before being deported with few exceptions. However, there are some potential problems with Census-based studies that could lead to inaccurate results. That’s where the second type of study comes in. The second type is a macro level analysis to judge the impact of immigration on crime rates, generally finding that increased immigration does not increase crime and sometimes even causes crime rates to fall. Type 1: Immigrant Crime – Censuses of the Institutionalized PopulationButcher and Piehl examine the incarceration rates for men aged 18-40 in the 1980, 1990, and 2000 Censuses. In each year immigrants are less likely to be incarcerated than natives with the gap widening each decade. By 2000, immigrants have incarceration rates that are one-fifth those of the native-born. Butcher and Piehl wrote another paper focusing on immigrant incarceration in California by looking at both property and violent crimes by city. Between years 2000 and 2005, California cities with large inflows of recent immigrants tended have lower violent crimes rates and the findings are statistically significant. During the same time period, there is no statistically significant relationship between immigration and property crime. Ewing, Martinez, and Rumbaut summarize their findings on criminality and immigration thusly:“[R]oughly 1.6 percent of immigrant males 18-39 are incarcerated, compared to 3.3 percent of the native-born. The disparity in incarceration rates has existed for decades, as evidenced by data from the 1980, 1990, and 2000 decennial census. In each of those years, the incarceration rates of the native-born were anywhere from two to five times higher than that of immigrants.”They continue by focusing on immigrant incarceration rates by country of origin in the 2010 Census. Less educated young Mexican, Salvadoran, and Guatemalan men (poorly educated young men are most likely to be incarcerated) make up the bulk of the unlawful immigrant population but have significantly lower incarceration rates than native-born men without a high-school diploma. In 2010, 10.7 percent of native-born men aged 18-39 without a high school degree were incarcerated compared to 2.8 percent of Mexican immigrants and 1.7 percent of Guatemalan and Salvadoran immigrants. These are similar to Rumbaut’s older research also based on Census data from 2000. Controlling for relevant observable factors, young uneducated immigrant men from Mexico, El Salvador, and Guatemala are less likely to be incarcerated than similarly situated native-born men.However, studies of immigrant criminality based on Census data alone could fail to give the full picture. First, many of the answers given to the Census may have been educated guesses from the Census workers and not the inmates. Second, the government has done a very poor job of gathering data on the nationality and immigration status of prisoners – even when it has tried. That biases me against the accuracy of prison surveys by the Census Bureau. Third, incarceration rates may better reflect the priorities of law enforcement than the true rates of criminal activity among certain populations.Type 2: Macro Level Analysis of Immigrant CriminalityTo avoid the potential Census data problems, other researchers have looked at crime rates and immigration on a macro scale. These investigations also capture other avenues through which immigration could cause crimes – for instance, by inducing an increase in native criminality or by being easy targets for native criminals.The phased rollout of the Secure Communities (S-COMM) immigration enforcement program provided a natural experiment. A recent paper by Thomas J. Miles and Adam B. Cox used the phased rollout to see how S-COMM affected crime rates per county. If immigrants were disproportionately criminal, then S-COMM would decrease the crime rates. They found that S-COMM “led to no meaningful reduction in the FBI index crime rate” including violent crimes. Relying on similar data with different specifications, Treyger et al. found that S-COMM did not decrease crime rates nor did it lead to an increase in discriminatory policing that some critics were worried about. According to both reports, the population of immigrants is either not correlated, or negatively correlated, with crime rates. Ousey and Kubrin looked at 159 cities at three dates between 1980 and 2000 and found that crime rates and levels of immigration are not correlated. They conclude that “[v]iolent crime is not a deleterious consequence of increased immigration.” Martinez looked at 111 U.S. cities with at least 5,000 Hispanics and found no statistically significant findings. Reid et al. looked at a sample of 150 Metropolitan Statistical Areas (MSAs) and found that levels of recent immigration had a statistically significant negative effect on homicide rates but no effect on property crime rates. They wrote, “[i]t appears that anti-immigrant sentiments that view immigrants as crime prone are not only inaccurate at the micro-level, they are also inaccurate at the macro-level … increased immigration may actually be beneficial in terms of lessening some types of crimes.” Wadsworth found that cities with greater growth in immigrant or new immigrant populations between 1990 and 2000 tended to have steeper decreases in homicide and robbery rates. Using panel data on U.S. counties, Spenkuch finds that a 10 percent increase in the share of immigrants increases the property crime rate by 1.2 percent. In other words, the average immigrant commits roughly 2.5 times as many property crimes as the average native but with no impact on violent crime rates. He finds that this effect on property crime rates is caused entirely by Mexican immigrants. Separating Mexicans from other immigrants, the former commit 3.5 to 5 times as many crimes as the average native. However, all other immigrants commit less than half as many crimes as natives. This is the most deleterious finding that I discovered. Stowell et al. looks at 103 different MSAs from 1994-2004 and finds that violent crime rates tended to decrease as the concentration of immigrants increased. An immigrant concentration two standard deviations above the mean translates into 40.5 fewer violent crimes per 100,000 compared to a decrease of 8.1 violent crimes in areas that experienced a change in immigration concentration two standard deviations below the mean. It is easy to focus on the horrible tragedies when somebody is murdered by an immigrant but it’s very hard to imagine all of the people who weren’t murdered because of the lower crime rates created by increased immigration. In their summary of the research on this topic, they write:“[T]he weight of the evidence suggests that immigration is not associated with increased levels of crime. To the extent that a relationship does exist, research often finds a negative effect of immigration on levels of crime, in general, and on homicide in particular. Some immigrants from certain countries of origin may be more crime prone than others, as Spenkuch finds above. To test this, Chalfin used rainfall patterns in Mexico to estimate inflows of Mexican immigrants. The idea is that lower rainfall and a decrease in agricultural productivity in Mexico would push marginal Mexican immigrants out of Mexico and into the U.S. labor market. Mexican rainfall patterns and the subsequent immigration had no effect on violent or property crime rates in major U.S. metropolitan areas. These trends have also been found on the local level. Davies and Fagan looked at crime and immigration patterns at the neighborhood level in New York City. They find that crime rates are not higher in areas with more immigrants. Sampson looked at Chicago and found that Hispanic immigrants were far less likely to commit a violent criminal act then either black or white native Chicagoans. Lee et al. found that trends in recent immigration are either not correlated with homicides or are negatively correlated in Miami, San Diego, and El Paso. The only exception is that there is a positive relationship between immigration and black homicide rates in San Diego. Numerousstudiesalso conclude that the high immigration rate of the 1990s significantly contributed to the precipitous crime decline of that decade. According to this theory, immigrants are less crime prone and have positive spillover effects like aiding in community redevelopment, rebuilding of local civil society in formerly decaying urban cores, and contributing to greater economic prosperity through pushing natives up the skills spectrum through complementary task specialization. Note on Illegal Immigration The public focus is on the crime rates of unauthorized or illegal immigrants. The research papers above mostly include all immigrants regardless of legal status. However, every problem with gathering data on immigrant criminality is multiplied for unauthorized immigrants. There is some work that can help shed light here.With particular implications for the murder of Kate Steinle, Hickman et al. look at the recidivism rates of 517 deportable and 780 nondeportable aliens released from the Los Angeles County Jail over a 30-day period in 2002. They found that there is no difference in the rearrest rate of deportable and nondeportable immigrants released from incarceration at the same place and time. Their paper is not entirely convincing for several reasons, the most important being that their sample does not include the higher risk inmates who were transferred to state prison and were subsequently released from there. There are also findings in their paper that seem to contradict their conclusion that aren’t adequately accounted for. This is only one study of one sample in one city but the results should be incorporated into any argument over sanctuary cities. ConclusionBoth the Census-data driven studies and macro-level studies find that immigrants are less crime-prone than natives with some small potential exceptions. There are numerous reasons why immigrant criminality is lower than native criminality. One explanation is that immigrants who commit crimes can be deported and thus are punished more for criminal behavior, making them less likely to break the law. Another explanation is that immigrants self-select for those willing to work rather than those willing to commit crimes. According to this “healthy immigrant thesis,” motivated and ambitious foreigners are more likely to immigrate and those folks are less likely to be criminals. This could explain why immigrants are less likely to engage in “anti-social” behaviors than natives despite having lower incomes. It’s also possible that more effective interior immigration enforcement is catching and deporting unlawful immigrants who are more likely to be criminals before they have a chance to be incarcerated. The above research is a vital and missing component in the debate over the supposed links between immigration and crime.

Under the Wisconsin Constitution Article I, Section 25 ("The people have the right to keep and bear arms for security, defense, hunting, recreation or any other lawful purpose.") there is a right to bear arms. But that does not mean anyone may carry a gun in Wisconsin.Besides Wisconsin law, federal law prohibits certain individuals from possessing firearms. Briefly, federal law does not permit you to have a gun if:

Are not at least 18 years old to purchase a long gun; 21 to buy a handgun.

Are a convicted felon.

Were convicted of a misdemeanor of domestic-violence.

Are subject of a restraining order.

Were dishonorably discharged from a branch of the U.S. Armed Forces.

Are living in the United States unlawfully.

Are mentally disabled.

Private, person-to-person weapons sales conducted at Wisconsin gun shows or over the Internet are exempt from federal laws and do not require background checks or waiting periods, but only if both the buyer and seller live in Wisconsin.Similarly, Wisconsin bars certain individuals from gun possession:

At 18 you can purchase a long gun, and at 21 you can purchase a handgun and/or get a concealed carry license. Note that this is purchase age not possession age. Wisconsin law generally provides that for hunting purposes, the minimum age for possession or control of a firearm is age 12. A person age 12 but under age 14 may not hunt without being accompanied by his or her parent, guardian or a person at least 18 years of age who is designated by the parent or guardian. A young person 12 to 14 years of age also may possess a firearm if he or she is enrolled in instruction under the state hunter education program and is carrying the firearm in a case, unloaded, to or from that class, or is handling or operating the firearm during that class under the supervision of an instructor.

people convicted of a felony in Wisconsin (or a crime in another state that would have been a felony if it had been committed in Wisconsin)

people adjudicated delinquent for an act that, if committed by an adult, would have been a felony

people found not guilty of a crime by reason of insanity, a mental disease, defect, or illness, or

those ordered not to possess a firearm under several specified Wisconsin laws.

Wisconsin also prohibits having a weapon in or near any of the following:

Secure area of an airport.

A courthouse or any other area that posts the prohibition of firearms at the site.

School zones.

Anywhere while you're under the influence of drugs or alcohol.

In a boat has the motor running, if a rifle (not a handgun) is loaded

The state preempts all firearm laws in the state and local authorities can’t have Laws/Ordinances against open carry. If you enter any property and the owner/responsible person ask you to leave you must leave. Failure to leave can result in Trespass Charges. The Minimum age for Open Carry is 18. In the past, some jurisdictions have tried to prosecute open-carry by equating the open carry of handguns with disorderly conduct. On April 20, 2009 the Wisconsin Attorney General's office released a memorandum to all law enforcement agencies stating that mere open carry of a firearm was not disorderly conduct, and instructed both law enforcement and the district attorneys to cease this practice.Wisconsin requires a concealed carry permit to carry a weapon concealed on (or near) you body or vehicle unless you are in your house, at your place of business, or on your own property. (Wis. Stat. § 941.23(2)(e).) You can carry an unconcealed handgun in a vehicle in Wisconsin but if you come within 1000 foot of a school you can be charged. You can transport within 1000 foot of a school without a permit/license to carry under Federal Code 18 USC 922 if the handgun is unloaded and secured.A rifle can be stored in sight or concealed but may not have ammunition in the chamber or magazine. It's best to keep the ammunition in the glove box. It also recommended that the firearm be kept out of reach when driving. Loading, or having a loaded, uncased handgun inside a vehicle was legalized beginning November 1, 2011. The firearm must not be "hidden from ordinary observation" while inside the vehicle unless the citizen has a license. Upon request by a law enforcement officer who is acting in an official capacity and with lawful authority, a licensee who is carrying a concealed weapon shall display to the officer his or her concealed weapon license.On December 7, 2011 Governor Walker signed a bill passing a Castle Doctrine for Wisconsin. The bill provides criminal immunity (WI statute 939.48(1m)) and protection from civil suits (WI statute 895.62 ) for homeowners or business owners who use a gun in self-defense while on their property, with the presumption that any action is justified. The law is a "stand your ground" law, which does not contain a duty to retreat. This applies at the user's private vehicle, business, and at their home. Protection extends to improvements only (driveway, sidewalk, patio, fence, garage, house...), not bare ground. Also, the criminal must have forcibly entered, or be in the process of attempting to forcibly enter, and the defender must be present in the home, car, or business.Machine guns (fully automatic firearms) are legal if the firearm is registered with the Bureau of Alcohol, Tobacco, Firearms & Explosives (BATFE), and the owner has received permission from the local sheriff or chief of police (941.26), or the weapon is exempted per statute 941.27. Short-barrel rifles and shotguns are legal if they are registered with ATF, state statute 941.28. Suppressors are legal if they are registered with ATF, statute 941.298

Rob Mitchell of The Boston Herald explained that “Deep in the mines, a distressed canary is a warning that there’s poison in the air. [In their book, The Miner's Canary] Professor Lani Guinier…and Gerald Torres…contend that in America, race is like a miner’s canary: Injustices experienced by people of color warn of systemic toxins that threaten everyone… In a passionate call for social change and progressive action, Guinier and Torres convincingly argue that a colorblind approach to deeply entrenched problems does not work; it only inhibits democratic engagement and reinforces existing power structures. Citing the Rev. Martin Luther King Jr.’s message that freeing black people from injustice will free America itself, Torres and Guinier urge progressives to use racial awareness as an entryway to political activism." Ultimately The Miner's Canary develops the idea of "political race," a concept that identifies racial literacy as a new way to think about social change in American society.In Utah v. Strieff, Justice Clarence Thomas, the court found that if an officer illegally stops an individual then discovers an arrest warrant—even for an incredibly minor crime, like a traffic violation—the stop is legitimized, and any evidence seized can be used in court. The only restriction is when an officer engages in “flagrant police misconduct,” which the decision declines to define.Justice Sonia Maria Sotomayor told us how dead our racial canaries are in America. “This case allows the police to stop you on the street, demand your identification, and check it for outstanding traffic warrants—even if you are doing nothing wrong,” Sotomayor writes, in a dissent joined in part by Justice Ruth Bader Ginsburg. “If the officer discovers a warrant for a fine you forgot to pay, courts will now excuse his illegal stop and will admit into evidence anything he happens to find by searching you after arresting you on the warrant.” In her dissent, Justice Sotomayor tried to wake up courts and the public to the fact that "it is no secret that people of color are disproportionate victims of [scrutiny by traffic stops.]....This case tells everyone, white and cblack, guilty and innocent, that an officer can verify your legal status any time. .....It says that your body is subject to invasion while courts excuse the violation of your rights. It implies that you are not a citizen of a democracy but the subject of a carceral state, just waiting to be cataloged..... We must not pretend that the countless people who are routinely targeted by police are “isolated.” They are the canaries in the coal mine whose deaths, civil and literal, warn us that no one can breathe in this atmosphere. They are the ones who recognize that unlawful police stops corrode all our civil liberties and threaten all our lives. Until their voices matter too, our justice system will continue to be anything but."

A popular government without popular information, or the means of acquiring it, is but a Prologue to a Farce or a Tragedy; or perhaps both. Knowledge will forever govern ignorance. And a people who mean to be their own Governors must arm themselves with the Power that knowledge gives.-James Madison

"Where does chocolate milk come from?" the Innovation Center for U.S. Dairy asked 1,000 American adults this April. Seven percent of American adults believe that chocolate milk comes from brown cows. “Responses came from all 50 states, and the regional response breakdown was fairly even, with a slight uptick (approx. 10% higher) in the South” spokeswoman Lisa McComb confirmed to HuffPost.

An effective American society requires people not to be stupid. Thankfully, Prof. Somin says that ignorance isn't the same as stupidity. Sometimes, he writes, it is a rational behavior based on conservation of knowledge and attention. "We all have limited time, energy, and attention," he says, "and so can learn only a small fraction of all the information out there. It makes sense for us to focus on that which is likely to be useful or interesting. For many people, large swathes of basic political and scientific facts don’t qualify."

So what do you focus on as useful or interesting? The latest in sports scores or what's on TV? what your friends are saying on social media? That is fine if that is not the only thing you do. But we may want to recall that the rising cost of ever more spectacular gladiatorial games, borne by Roman emperors and therefore the state, has also been posited as a theory for the decline of the Roman Empire. Cicero explicitly recognized this towards the end of the Republic: 'the judgement and wishes of the Roman people about public affairs can be most clearly expressed in three places: public assemblies, elections, and at plays or gladiatorial shows'. He challenged a political opponent: 'Give yourself to the people. Entrust yourself to the Games. Are you terrified of not being applauded?' So how far are we from deciding the truth based upon American gladiatorial games?

Howard Beal would know. In the movie Network, Beale, the anchorman for the UBS Evening News, struggles to accept the ramifications of the social ailments and depravity existing in the world. His producers exploit him for high ratings and avoid giving him the psychiatric assistance that some (especially his companion Max Schumacher) think he needs. The image of Beale in a beige coat with his wet hair plastered to his head, standing up during the middle of his newscast saying, "I'm as mad as hell, and I'm not going to take this anymore!" earns great ratings. Beale's career as "The Mad Prophet of the Airwaves" concludes with a threat to kill himself on TV. Beal apologizes to his viewers, telling them he "ran out of bullshit." Viewers respond positively and he is given his own show where he can say whatever he likes. The movie ends with Beal's murder on national television and a voice over proclaims him "the first known instance of a man who was killed because he had lousy ratings."

Admit it. You would be watching as you sipped your chocolate milk and wondered how something that delicious existed...

In cases where a judge has to make a determination of who is telling the truth between a criminal defendant and a police officer, no one would be surprised to hear the court will almost always believe the police officer. But why?

The rules of evidence say all witnesses, even criminal defendants, are just as competent to testify as any other person. State v. Albright, 96 Wis. 2d 122, 127, 291 N.W. 2d 487 (1980); Voight v. State, 61 Wis. 2d 17, 20, 211 N.W. 2d 445 (1973). Likewise, saying police officers should automatically be believed over a criminal since in fact some police officers are criminals. It can no longer be said that the officer testifying in court has no criminal conviction. The dirty secret that some courts and prosecutors do not want to admit is that some police officers are - ranking from street cop to captain - have been disciplined for violating the laws and ordinances they were sworn to uphold. At least six officers disciplined by the department for illegal behavior suffered no legal consequences whatsoever. One was Reginald Hampton, accused of sexually assaulting two women he met on duty. Another was Mark Kapusta, suspended after a woman said he pointed a gun at her head during a drunken road-rage incident. Neither officer was charged or ticketed. Gina Barton, "At least 93 Milwaukee police officers have been disciplined for violating law,"Milwaukee Journal Sentinel. Simply put, the system allows police officers to keep their jobs despite run-ins with the law. "Both Sides of the Law," Milwaukee Journal. Apparently, some judges are not aware that simply because someone has a criminal conviction is not a bar to someone being hired as a police officer. Dan Zimmerman, "Milwaukee Hires Cops with Criminal Records. And They're Just Fine with That,"The Truth about guns.com

Not only are some cops criminals, but many cops lie when they testify. Disclosures about rampant police perjury cannot possibly come as a surprise. "Testilying" -- as the police call it -- has long been an open secret among prosecutors, defense lawyers and judges. Irving Younger, a onetime New York City Criminal Court judge, described police testimony in search and seizure cases this way: "When one . . . looks at a series of cases, [ it ] then becomes apparent that policemen are committing perjury at least in some of them, and perhaps in nearly all of them." Alan M. Dershowitz, "Controlling the Cops; Accomplices To Perjury,"The New York Times. Peter Keane, a former San Francisco Police commissioner, wrote an article in The San Francisco Chronicle decrying a police culture that treats lying as the norm: “Police officer perjury in court to justify illegal dope searches is commonplace. One of the dirty little not-so-secret secrets of the criminal justice system is undercover narcotics officers intentionally lying under oath. It is a perversion of the American justice system that strikes directly at the rule of law. Yet it is the routine way of doing business in courtrooms everywhere in America.” Michelle Alexander, "Why police lie under oath" The New York Times To be sure, some judges no longer put on blinders when it comes to police officer testimony. One judge railed against what some other judges and lawyers in the criminal justice system say occurs far too often: police officers shading the truth in subtle ways or outright lying from the witness stand. The result, they said, is that sometimes the innocent go to prison, the guilty go free and the criminal justice system is tarnished. Steve Mills and Todd Lighty, "Cops rarely punished when judges find testimony false, questionable,"Chicago Tribune.

So again, let me ask, why believe a cop over a defendant? Interestingly, in Judicial Presumption of Police Expertise 130 HARV. L. REV. 1995 2017 Anna Lvovsky has given us an important and edifying window into the much contested phenomenon of judicial deference to the police. As Lvovksy sees it, judges jumped from deferring to police testimony about specific facts in specific cases to deferring to police expertise generally. Next, judges went from deferring to the actions of police in the executive realm to deferring to their views to support legislative enactments. Finally, judges displayed serious analytic biases that caused them to just say yes when it comes to policing. “This expansion of police expertise undercuts a core safety net against overdeference in the Fourth Amendment context.” Id. at 2070-71. Lvovsky explores what one might call the “politics” of judging the police. The heart of this story is that — for whatever reasons — judges (especially elected judges) want to appear “tough on crime” and a key way to do that is by buying hook, line, and sinker into what the police say. Id. at 2053-58. Maybe judicial deference to police is not grounded in a misguided view of police expertise grounded in exposure to the police in all areas, but instead reflects a conscious desire not to buck what the police say — for any of a number of reasons, from thinking that the defendants they see are guilty as hell, to wanting to appease the public’s desire to be tough on criminals — and thus deferring to the police as experts in testimony.

Want a good employee? Hire one with a criminal record. In one of the first systematic evaluations of ex-felony offenders in the workplace, researchers from Harvard University and the University of Massachusetts Amherst assessed whether the common reasons employers give against hiring criminals are borne out in the rare instances when they are hired. Using original data assembled from military records that received through a FOIA request, we follow 1.3 million ex-offender and non-offender enlistees who enlisted during 2002-2009. It was found that individuals who have been arrested for felony-level offenses have similar attrition rates to those with no criminal record. Statistical models show they are no more likely to be discharged for the negative reasons employers often assume. In fact, the only cause of abbreviated service that appears to differ significantly for those with and without serious criminal records is a higher rate of death in the course of service observed among our sample members with criminal records. As for promotional trajectories, it was found that individuals with felony-level criminal backgrounds are promoted more quickly and to higher ranks than other enlistees. The military’s criminal forgiveness process holds promise for the civilian sector, showing that proper screening can result in success to the mutual benefit of employers and individuals with criminal histories. https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwjj1OidqqrUAhXKPiYKHU65C_EQFggiMAA&url=https%3A%2F%2Fpaa.confex.com%2Fpaa%2F2016%2Fmediafile%2FExtendedAbstract%2FPaper2871%2FASRDraft01222016.pdf&usg=AFQjCNGieL3z2I7Wmnv9ckqGkXNFMJ6k8g

Various newsoutlets are reporting that former FBI Director James Comey will have the nation captivated next Thursday when he testifies before a Senate panel about the stunning accusations that President Donald Trump pressured him to end his investigation into his former national security adviser's ties to Russia. But can Trump stop Comey from talking?Courts may require witnesses to appear and give testimony in court. A privilege is an exception to this rule. Some privileges are actually a constitutional right. Privileges allow an individual to object to proposed testimony regarding communications that they had with a person in a confidential relationship. There are different privileges that are recognized under state and federal law.In the United States government, executive privilege is the power claimed by the President of the United States and other members of the executive branch to resist certain subpoenas and other interventions by the legislative and judicial branches of government to access information and personnel relating to the executive branch. The Supreme Court confirmed the legitimacy of this doctrine in United States v. Nixon, but only to the extent of confirming that there is a qualified privilege. Once invoked, a presumption of privilege is established, requiring the prosecutor to make a "sufficient showing" that the "Presidential material" is "essential to the justice of the case" (418 U.S. at 713-14). Chief Justice Burger further stated that executive privilege would most effectively apply when the oversight of the executive would impair that branch's national security concerns. Chief Justice Burger, writing for the majority in US v. Nixon noted: "Whatever the nature of the privilege of confidentiality of Presidential communications in the exercise of Art. II powers, the privilege can be said to derive from the supremacy of each branch within its own assigned area of constitutional duties. Certain powers and privileges flow from the nature of enumerated powers; the protection of the confidentiality of Presidential communications has similar constitutional underpinnings." Because Nixon had asserted only a generalized need for confidentiality, the Court held that the larger public interest in obtaining the truth in the context of a criminal prosecution took precedence.A privilege guaranteed by the Fifth Amendment to the Constitution bans a a witness from being compelled to give testimony that is self-incriminating. A witness in “any proceeding, civil or criminal, administrative or judicial, investigatory or adjudicatory” may assert the privilege against self-incrimination. Kastigar v. U.S., 406 U.S. 441, 444-45 (1972). The assertion must be related to the witness’s “reasonabl[e] belie[f] that the information sought, or discoverable as a result of his testimony, could be used in a subsequent . . . criminal proceeding.” U.S. v. Balsys, 524 U.S. 666, 672 (1999). The privilege applies generally only to testimonial evidence. See, e.g., Oregon v. Elstad, 470 U.S. 298, 304 (1985) (“The Fifth Amendment, of course, is not concerned with nontestimonial evidence.”). Physical evidence is not testimonial. See, e.g., Commonwealth v. Conkey, 430 Mass. 139, 142 (1999) (“If evidence sought is real or physical evidence, such as hair and blood samples, voice exemplars, fingerprints, lineups, sobriety tests, or breathalyzer tests, art. 12 does not protect a person from having to provide such evidence.”). However, when admitted to show consciousness of guilt, conduct evidence is “always testimonial because it tends to demonstrate that the defendant knew he was guilty,” e.g., threat or intimidation of potential witness, attempt to commit suicide, refusal to turn over physical evidence, refusal to take field sobriety test, destruction of evidence, flight, altered appearance, and false statements. Id. at 142 (internal citations omitted).If a witness testifies about incriminating matters and does not assert his privilege against self-incrimination, it is waived. U.S. v. Monia, 317 U.S. 424, 427 (1943). However, if a witness is compelled to testify, the witness has no reason to assert the privilege until “testimony sought to be elicited will in fact tend to incriminate.” Brown v. U.S., 356 U.S. 148, 156 (1958)(“He must be able to raise the bar at the point in his testimony when his immunity becomes operated.”).“It is well-established that a witness, in a single proceeding, may not testify voluntarily about a subject and then invoke the privilege against self-incrimination when questioned about the details.” Mitchell v. U.S., 526 U.S. 314, 321 (1999); Brown v. U.S., 356 U.S. at 156 (witness cannot testify on her own behalf and then assert the privilege during cross examination “on matters raised by her own testimony on direct examination.”). A criminal defendant “has no right to set forth to [the factfinder] all the facts which tend in his favor without laying himself open to a cross examination upon those facts.” Brown, 356 U.S. at 155 (internal quotation omitted). When a witness testifies voluntarily, “certainly if he is a party, [he] determines the area of disclosure and therefore of inquiry.” Id. at 155-156. The witness, therefore, can face cross examination on those facts which he puts into dispute. Id.If a witness waives his privilege in regard to a particular topic, he does not waive his privilege as to all possible related topics. See Rogers v. U.S., 340 U.S. 367, 373-374 (1951); Hashagan v. U.S., 283 F.2d 345, 352 (9th Cir. 1960). See generally 3 Nancy Hollander et al., Wharton’s Criminal Procedure, §20:12, at 20-46 – 20-49 (14th ed. 2008) (explaining precedent in regard to waiver and related topics). If a witness has testified regarding an incriminating matter, he has waived his privilege in regard to that matter; however, he has not waived the privilege in regard to testimony which might further incriminate him regarding other crimes. Hashagan, 283 F.2d at 354.